Merge pull request #181 from alpacahq/data_v2

Smal fixes (data source, date format)

Author: camelpac

alpaca_backtrader_api/alpacastore.py

@@ -128,6 +128,7 @@ def __init__(
         self.conn = Stream(api_key,
                            api_secret,
                            base_url,
+                           data_stream_url=data_url,
                            data_feed=data_feed)
         self.instrument = instrument
         self.method = method
@@ -440,7 +441,8 @@ def _make_sure_dates_are_initialized_properly(self, dtbegin, dtend,
         if not dtend:
             dtend = pd.Timestamp('now', tz=NY)
         else:
-            dtend = pd.Timestamp(pytz.timezone('UTC').localize(dtend))
+            dtend = pd.Timestamp(pytz.timezone('UTC').localize(dtend)) if \
+              not dtend.tzname() else dtend
         if granularity == Granularity.Minute:
             calendar = trading_calendars.get_calendar(name='NYSE')
             while not calendar.is_open_on_minute(dtend):
@@ -454,7 +456,8 @@ def _make_sure_dates_are_initialized_properly(self, dtbegin, dtend,
             delta = timedelta(days=days)
             dtbegin = dtend - delta
         else:
-            dtbegin = pd.Timestamp(pytz.timezone('UTC').localize(dtbegin))
+            dtbegin = pd.Timestamp(pytz.timezone('UTC').localize(dtbegin)) if \
+              not dtbegin.tzname() else dtbegin
         while dtbegin > dtend:
             # if we start the script during market hours we could get this
             # situation. this resolves that.